mcgrath



W. L. MCGBAT ENGINE STARTER.

APPLICATION FILED WAR. 1. 1919.

Patented Oct. 31, 1922.

2 SHEETSSHEET 1 w. L. McGRATH. ENGINE STARTER.

APPLICATION FILED MAR. 1,19I9- Patented Oct. 31, 1922.

2 SHEETS SHEET 2| JAQ,

Patented Oct. 31, 1922. I 1,433,833 UNITED STATES PATENT OFFICE.

WILLIAM L. MCGRATH, OF ELMIRA, NEW YORK, ASSIG'NOR TO ECLIPSE MACHINECOMPANY, OF ELMIRA, NEW YORK, A CORPORATION OF NE\V YORK.

ENGINE STARTER.

Application filed March 1, 1919. Serial No. 279,982.

To allevizowz-it may concern: starting motor A, a driving head 2 securedBe it known that I, VVILLIAM L. Mcto the. outer end of the drivingshaft, :1

GRATH, a citizen of the United States, residcoiled driving springsecured to a screw ing at Elmira. in the county of Chemung' shaft 4:which is in the form of a hollow 5 and State of New York, have inventedcersleeve mounted on the driving shaft, a p1ni tain new and usefulImprovements in Enion screw threaded. upon the screw threads gineStarters, of which the following is :i l of such shaft and adapted tomesh with specification. the teeth (3 of the lily wheel 6 or otherengineluv invention relates to starters for interdriven member.

10 nal combustion engines or the like, and the The stop nut 7 instead ofbeing an ordi- 6 particular object thereof is to improve the nary collarsecured to one end of a screw drive or transmission thereof. The driveshaftto form an abutment or stop for the with which my invention isconcerned is pinion is provided with a cylindrical exof the automaticscrew shaft type charactertension 7 projecting towards the pinion.

ized by a rotatable screw shaft driven by This stop nut is secured tothe screw shaft 70 a starting motor and having screw-threaded .in anysuitable manner as by means of thereon a pinion adapted to beautomatically threading. The pinion is provided with :1 advanced intomesh with an engine driven central bore which is screw-threaded formember such as the fly wheel, by the rotation a portion of its length toloosely fit the of such screw shaft. This pinion loosely screw threadson the shaft, and is counter 75 threaded upon the screw shaft so that itwill bored at 5 for a portion of its length, not be inclined to bindthereon at the time which counterbore is of a diameter to rather whenthe pinion is to be rotarily idle and accurately fit the cylindricalextension for to be advanced longitudinally as abov the purpose ofcentering the pinion at the 2 stated. When the pinion is in full meshwill: end of its longitudinal movement for mesht0 the fly wheel it isdesirable that such pinion ing, and also of Running a solid and conshallbe accurately centered on the. shaft and tiinuous support for suchpinion during its shall be firmly supported thereby, in order rotationwhen driving the fly wheel. By to properly mesh with the fly wheel andpreference the outer corner of the cylindrialso to avoid noise duringtheir rotary movecal extension is inclined or beveled at 7 L- ment aswell as to prevent wear between the to assist the pinion in thecentering operapinion and the screw shaft. According to tion. Therelative length of this extension my present invention I attain thisobject and counter-bore are such that at the end ofv by providing at oneend of the screw shaft its longitudinal movement to the left the end apart (integral or separate from the shaft) of the pinion will abutagainst the annular 90 which accurately fits a plain counterborodshoulder 7 of the stop nut which thus re- )ortion of the central bore ofthe pinion. ceives all of the stopping contact and pros The inventionmay be embodied in different sure of the pinion.

forms of constructions, several of which are According to themodification shown in herein shown and described. Fig. 5, the centeringmeans is an integral i" In the drawin Fig. l is a sectional plan part ofthe screw shaft itself, comprising of a starter inclu ing a driveembodying my plain portion 49 of suitable diameter which invention;Figs. 2 and 3 sections on the means the same or larger diameter than theline 2--2, 33 of Fig. 1; 4: a detail outside diameter of the screwthreads l,

view in elevation of the stop nut and sleeve but, in the presentinstance, of slightly and a portion of the screw shaft; Figs. 5', largerdiameter. The counterbore 5 of the (3 and 7 detail sections ofmodifications of pinion fits over this portion 49 in the same the samegeneral type; Fig. 8 a sectional way and with the same results as in thecase elevation of a modification of another type, of the other form ofconstruction. In this 50 and Fig. 9 a section on the line 99 ofconstruction, the stop shoulder 4. is integral Fig. 8. with. the shaftbut obviously be formed Referring to the embodiment of my invenby aseparate nut, like nut 7 as shown in tion as shown in Figs. 1 to 4, thedrive llllli Fig. 6. In Fig. 7 I have shown another tinted comprises adriving shaft 1 which modification ol thc same general type as may bethe extended armature shail of a above described but difiering from thatof 1.

Fig. l in that the stop nut 8 is of plain form. The centering andsupporting means is a plain ring 9 interposed between said nut and theend of the screw threads at. This particular construction has theadvantage of economy and facility in manufacture inasmuch as the ring,being separate, can be separately machined or ground and treated.

By means oi: my invention 1 am enabled to obtain the advantage of aloose fit be ween the threads of the screw shaft and the pinion and toprovide for .;he proper positioning and support of such pinion duringthe time when it is in driving: operation.

in l 8 and I have shown a modified construction of? a somewhat diilerenttype ot drive according); to which the pinion is not sciew-threaded on ashaft but controlled in its operation by a nut or control member whichis screw-threaded onto such shaft. lleierring to .l ig. S, the motor hasan. extended. armature shaft which consists of a plain portion 10 and ascrew-threeded portion 1.1. The pinion 12 slides on said. plain portionand is controlled by the nut 13 which is screw-threaded on said, screwshaft and is connected. to the pinion by the driving spring let. i

' As shown the pinion does not fit the outer end oi the plain portion ofthe shaft with any accuracy or closeness but has a loose fit therewithwhen in its. normal or home position thereby leaving an annular space 17be tween the pinion and the shaft 10, as illustrated. However, the innerportion o't this shaft is slightly enlarged in diameter and carefullymachined so that the pinion here will. fit accurately thereon when it isin mesh with the fly wheel. This enlarged portion is indicated at 10 andthe result thereof is substantially the same with respect to the actionof this pinion as inrespect to the pinions oil? the previously describedconstructions.

I claim:

1. In an engine starter a drive or transmission including a screw shafta driving member scrcw-threaded thereon iior longitudinal movement alongthe shaft to engage a member oi the engine to be started, and a stop nutsecured to the screw shaft and having an extension projecting; towardsthe driving men'iber, which latter has a countew bore adapted to litupon. such. extension.

2. In an engine starter, a drive or trans mission including :1 screwshaft. a driving:

member screw-threeded thereon itor loniritudinal movement along the shail; to engage u member 01 the engine to be sinrted. and a stop nutsecured to the screw shziitt and he inn i1 cylindrical extension ol'less dimneter than the nut. such driving member having: :1 counteirboreadapted to [it upon the sleeve.

in an engine starter, a drive or transmission including :i screw shaft,a drivimz member screw-tlneaded thereon :tor longitudinal movement alongthe shaft to engage a n'ieinber oi the engine to be started, and a stopnut secured to the screw shaft end having an extension projectingtowards the driving member which has a counterbore adapted to [it uponsuch extension, the outer corner oi said extension being shaped toinsure centering; oi the driving; member.

at. In an engine starter, a drive or-trans mission including;- a screwshaft. a driving; member screw threaded thereon for longitudinalIDUYQHlQH Z along the shaft to engage a member oi the engine to bestarted, and a stop nut secured to the screw shaft and having anextension projecting towards the driving member, which has acountei'bore adapted to fit such extension, said counterbore heir longerthan the entensicn to permit the driving);' member to abut the stop nutitself. I

ll lz ihliih'l L. lvioGl-iilti.

